public class Chatbot {
    private static final String PREF_NODE = "com.pach.gsm.chatbot";
    private static final String KEY_SESSION_ID = "session_uuid";
    private static Chatbot instance;



    private static Whatsapp api;



    private boolean loggedIn;


    private boolean wasLoggedIn;
    private boolean turnedOn;



    private boolean enabled;
    private boolean disconnected;


    public static Chatbot getInstance() {
        if (instance == null) {
            instance = new Chatbot();
        }
        return instance;
    }


    public boolean isLoggedIn() {
        return loggedIn;
    }

    public void setLoggedIn(boolean loggedIn) {
        this.loggedIn = loggedIn;
    }


    public boolean isTurnedOn() {
        return turnedOn;
    }

    public void setTurnedOn(boolean turnedOn) {
        this.turnedOn = turnedOn;
    }

    public static Whatsapp getApi() {
        return api;
    }

    public static void setApi(Whatsapp api) {
        Chatbot.api = api;
    }

    public boolean isDisconnected() {
        return disconnected;
    }

    public void setDisconnected(boolean disconnected) {
        this.disconnected = disconnected;
    }


    private UUID loadOrCreateUuid() {
        Preferences prefs = Preferences.userRoot().node(PREF_NODE);
        String raw = prefs.get(KEY_SESSION_ID, "");
        try {
            if (raw == null || raw.isBlank()) {
                UUID fresh = UUID.randomUUID();
                prefs.put(KEY_SESSION_ID, fresh.toString());
                return fresh;
            }
            return UUID.fromString(raw);
        } catch (IllegalArgumentException bad) {
            UUID fresh = UUID.randomUUID();
            prefs.put(KEY_SESSION_ID, fresh.toString());
            return fresh;
        }
    }

    public void initializeChatbot(){

        String baseDir = System.getProperty("user.home") + File.separator + "Documents" + File.separator + "GSM" + File.separator + "qr.png";
        Path qrFile = Path.of(baseDir);
        try {
            Files.createDirectories(qrFile.getParent());
        } catch (Exception e) {
            throw new RuntimeException("Could not prepare QR directory", e);
        }

        api = Whatsapp.builder()
                .webClient()
                .newConnection(loadOrCreateUuid())
                .historySetting(WhatsappWebHistoryPolicy.discard(false))
                .unregistered(
                        WhatsappVerificationHandler.Web.QrCode.toFile(
                                qrFile,
                                savedPath -> {
                                    System.out.println("✅ QR Code saved at: " + savedPath.toAbsolutePath());
                                }
                        )
                )
                .addLoggedInListener(api -> {
                    System.out.println("✅ Whatsapp logged in");
                    setLoggedIn(true);
                    setWasLoggedIn(false);
                    setDisconnected(false);
                })
                .addDisconnectedListener(reason -> {
                    System.out.println("❌ Whatsapp disconnected " +  reason);
                    setDisconnected(true);
                    setLoggedIn(false);
                })
                /*.addListener(new SalesListener())*/
                .connect();

    }

    public void qrImageThread(ImageView qrImageView) {
        Thread checker = new Thread(() -> {
            String baseDir = System.getProperty("user.home") + File.separator + "Documents" + File.separator + "GSM" + File.separator + "qr.png";
            File qrFile = new File(baseDir);

            while (true) {
                if (Authentication.checkIfOnline()) {

                    // If we are disconnected but file exists
                    if (!isLoggedIn() && qrFile.exists()) {
                        Platform.runLater(() -> {
                            qrImageView.setImage(new Image(qrFile.toURI().toString()));
                        });
                    } else if (!isLoggedIn() && wasLoggedIn()){
                        Platform.runLater(() -> {
                            qrImageView.setImage(new Image(qrFile.toURI().toString()));
                        });
                    } else {
                        qrImageView.setImage(null);
                    }
                }
                try {
                    Thread.sleep(5000);
                } catch (InterruptedException e) {
                    System.out.println("❌ QR Image thread interrupted: " + e.getMessage());
                    break;
                }
            }
        });

        checker.setDaemon(true);
        checker.start();
    }



    public void logout(){
        if (isLoggedIn()){
            api.logout();
            api.store().deleteSession();
            System.out.println("✅ WhatsApp session disconnected successfully & session deleted!");
            setLoggedIn(false);
            setWasLoggedIn(true);
            setDisconnected(true);
            Chatbot.getInstance().initializeChatbot();
        } else {
            System.out.println("❌ Not connected, can't log out! ");
        }

    }


    public void sendTestMessage(String groupName){
        var chat = Chatbot.getApi().store()
                .findChatByName(groupName)
                .orElseThrow(() -> new NoSuchElementException("❌ Chat not found!"));
        Chatbot.getApi().sendMessage(chat, "Hello there I'm using Garage Sale Manager 🤓");
    }


    public boolean isEnabled() {
        return enabled;
    }

    public void setEnabled(boolean enabled) {
        this.enabled = enabled;
    }


    public List<String> getAllChats() {
        return Chatbot.getApi()
                .store()
                .chats()
                .stream()
                .filter(chat -> chat.name() != null && !chat.name().isBlank()) // has a display name
                .map(Chat::name)
                .distinct()
                .sorted(String.CASE_INSENSITIVE_ORDER)
                .toList();
    }



    public boolean wasLoggedIn() {
        return wasLoggedIn;
    }

    public void setWasLoggedIn(boolean wasLoggedIn) {
        this.wasLoggedIn = wasLoggedIn;
    }



}